Abstract: A plate includes: a main body; a flow channel provided in the main body and configured to flow inert gas therein; a cover configured to cover a surface of the main body where the flow channel is formed; a buried member buried in an opening of the flow channel, the buried member including a buried portion fixed to the flow channel and made of dense ceramic, and a flow portion held by the buried portion and configured to let the inert gas flow from an inside to an outside of the main body, at least a part of the flow portion being made of porous ceramic; and a plurality of through holes provided in the flow portion. A ratio of a diameter of an outer circumference of the buried portion to a diameter of a smallest circle among circles including all of the through holes is 1.2 or higher.

Abstract: A stage includes a base material having a first surface and a second surface adjacent to the first surface, and an insulating film including a plurality of particles, each of the plurality of particles having a flat surface. The flat surface included in the insulating film is provided along the first surface and the second surface. The base material includes a third surface in a direction 180 degrees opposite to the first surface, and a part of the flat surface included in the insulating film is provided along the third surface, and a surface obtained by extending the first surface and a surface obtained by extending the second surface intersect at 90 degrees. The base material includes a third surface in a direction 180 degrees opposite to the first surface, and a part of the flat surface included in the insulating film is provided along the third surface.

Abstract: A member for a plasma processing device includes: an aluminum base material; and an oxide film formed on the aluminum base material and having a porous structure, the oxide film including a first oxide film formed on a surface of the aluminum base material, a second oxide film formed on the first oxide film, and a third oxide film formed on the second oxide film, wherein the first oxide film is harder than the second oxide film and the third oxide film, and a hole formed in each of the first oxide film, the second oxide film and the third oxide film is sealed.